Effect of the symmetric stretch on the dipole polarizability of the cyclic form of the ozone molecule: a study based on high-level ab initio and density functional theory calculations Anastasios Haskopoulos, George Maroulis * Department of Chemistry, University of Patras, Caratheodory Street, GR-26500 Patras, Greece Received 28 June 2004; in final form 20 August 2004 Available online 15 September 2004 Abstract We have calculated the effect of the symmetric stretching on the dipole polarizability (a ab ) of the cyclic form of ozone, O 3 (D 3h ). We have used both conventional ab initio and density functional theory methods. All basis sets have been especially designed for polarizability calculations on O 3 (D 3h ). At the CCSD(T)/[9s6p5d1f] level of theory the a ab invariants change rapidly around R e = 1.444 A ˚ as  aðRÞ=e 2 a 2 0 E 1 h ¼ 16:49 þ 8:68ðR  R e Þþ 0:38ðR  R e Þ 2  2:63ðR  R e Þ 3 þ 0:51ðR  R e Þ 4 ; DaðRÞ=e 2 a 2 0 E 1 h ¼6:79  7:93ðR  R e Þþ 0:32ðR  R e Þ 2 þ 2:15ðR  R e Þ 3 : The B3LYP, B3P86 and B3PW91 density functional theory methods agree quite well with the most accurate conventional ab initio values for the mean polarizability at R e but tend to overestimate the magnitude of the anisotropy. The same trend is very much obvious for the derivatives ðd a=dRÞ e and (dDa/R) e . Ó 2004 Elsevier B.V. All rights reserved. 1. Introduction and theory The 1 A 1 ground state of ozone has two well-defined minima which correspond to an open (C 2v ) and a closed (D 3h ) form [1–3]. Although the open structure has been extensively studied experimentally, cyclic ozone has only recently been identified in MgO(1 1 1) surface recon- structions by Plass et al. [4]. The O–O bond length is 1.2717 A ˚ for the open [5] but much longer at 1.444 A ˚ for the closed form [6]. Recent theoretical work has shown that O 3 (D 3h ) is less polarizable than O 3 (C 2v ) [7,8]. The mean and the anisotropy of the dipole polar- izability are  a ¼ 19:27 and |Da| = 18.13 for O 3 (C 2v ) and 16.50 and 6:79 e 2 a 2 0 E 1 h , respectively, for O 3 (D 3h ) [8]. Moreover, from a computational point of view, the cal- culation of the electric properties of O 3 (D 3h ) seems to be less of a problem than in the case of O 3 (C 2v ) [8,9]. In this study we present a detailed study of the effect of the symmetric stretching on the dipole polarizability of cyc- lic ozone. Our main goal is to examine closely the stabil- ity of the dipole polarizability derivatives at higher levels of theory. These properties are of central importance to the determination of Raman intensities [10–12]. In previ- ous work we relied exclusively on conventional ab initio methods [7,8]. In our present effort we include three widely used density functional theory (DFT) methods. As DFT methods are now routinely used in many areas of computational quantum chemistry it is imperative to assess their predictive capability in electric polarizability calculations [13–15]. 0009-2614/$ - see front matter Ó 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.cplett.2004.08.128 * Corresponding author. E-mail address: maroulis@upatras.gr (G. Maroulis). www.elsevier.com/locate/cplett Chemical Physics Letters 397 (2004) 253–257